Test tapes for analyzing body fluids such as blood or urine can be used to detect components (analytes) in the body fluid. The tapes are generally provided in portable devices that operate automatically and can also be used by laymen to carry out the required analytical steps in a simple and rapid manner. A plurality of test fields each provided with a suitable test chemistry are arranged consecutively on a test tape wound on a reel, in contrast to conventional individual test strips. A sample of the body fluid is applied to a test field that is brought into an active position of an analytical system by advancing the tape, such as in a reel-to-reel configuration, in order to then be able to carry out a test, for example by means of an optical or electrochemical analysis. As in any reel-to-reel tape advancing system, fluctuations can occur in the moment of the mechanical load occurring on the tape transport path. Such fluctuations may be due to friction, increasing diameter of the used portion of the tape being wound on the drawing reel, and/or the resulting changes in speed. In an optimal system, the fluctuations should not have any effect on the exact positioning of the test fields at the active position for measurement or sample application. Nevertheless, if tape-positioning drives with positioning transmitters on their shafts or coupled machine components are used for advancing the tape, the mechanical tolerances of structural elements of the system, variations in the diameter of the tape reel, and tape slippage can all lead to deviations from the targeted position for a test field being brought into the active position.
In DE 103 43 896 A1, filed by the applicant and incorporated by reference herein in its entirety, various functional fields next to the test fields for a test tape are disclosed for purposes of providing user information or instructions for special instrument functions.
On the basis of the foregoing, the object of the invention is to further improve the prior art and to optimize the functionality of test tape type products, particularly in connection with positioning accuracy.
The combination of features stated in the claims are proposed to achieve this object.